Freezing Eggs-Science Helping to Build Families
The concept of being able to successfully freeze and subsequently thaw the unfertilized human egg (oocyte) has revolutionized the field of Reproductive Medicine. Previously less successful slow-freeze techniques have been essentially replaced by the rapid-freeze techniques, with close to 100% viability rates, and pregnancy rates comparable to embryo freeze and fresh cycles. This advance in technology has extended the possibilities for use of this process, and has helped empower women and couples to have an additional option to accomplish their dream of building a family.
Technique for Egg Freezing- the human egg is obtained via an In-Vitro Fertilization (IVF) cycle, in which the woman is stimulated with hormonal injections to induce super ovulation, or enhanced production of eggs. After a 10-12 day average stimulation, the woman undergoes a trans vaginal, ultrasound-guided oocyte collection (retrieval) under anesthesia to collect the eggs. The eggs obtained with this process would then be cryo-preserved (frozen) using vitrification, or rapid freeze technology, using high concentrations of cryo-protectants, or chemicals designed to protect the eggs from the potentially negative effects of the freezing process. The eggs are then placed in liquid nitrogen for long-term storage.
Indications for Egg Freezing
1. Fertility Preservation prior to cancer therapy- one of the most critical indications for egg freezing is the ability to offer preservation of fertility for women facing chemotherapy as part of their cancer treatments. These treatments can lead to permanent loss of reproductive potential for women due destruction of their eggs as a direct result of the chemotherapy, with premature ovarian failure and early menopause. The older the woman is at the time of chemotherapy, the higher the likelihood that permanent ovarian failure will occur as a result of the chemotherapy. Even with a diagnosis of cancer, fertility preservation with egg freezing can be safely performed in many cases prior to chemotherapy, in order to ensure future fertility potential. Reproductive Endocrinologists work closely with medical and GYN oncologists to ensure the treatments are safe and tailored to the persons’ needs.
2. Elective egg freezing- increasingly, women are opting to pursue egg freezing due to career and life plans. Given the fact that women are born with all the eggs they will have in their lifetime, with a progressive loss of reproductive function in the late 30’s and 40’s, the ability to freeze one’s eggs earlier in life becomes an attractive possibility to ensure future fertility. The eggs frozen earlier in ones’ reproductive life are of higher quality, with enhanced success to achieve successful pregnancy, with less miscarriage and genetic risks. The increased success of egg freezing, along with improved strategies to help reduce cost, has made egg freezing more widely accessible to women seeking this medical treatment.
3. Egg Freezing as part of Assisted Reproductive Technology (ART) Treatments- ART, which encompasses IVF and related treatments, is increasingly using egg freezing as part of our protocols. In the event that no sperm is available on the day of an IVF procedure, the couple can elect to freeze eggs, with excellent expectation that future fertilization and successful pregnancy can be accomplished when any sperm issue has been resolved. From a religious/ethical perspective, many couples have strong personal beliefs regarding the freezing of embryos, and request freezing for eggs that are not immediately fertilized. In certain circumstances, even in a relationship, a woman for personal reasons might opt to request egg freezing for a portion of eggs obtained through an IVF cycle.
4. Donor Egg/Egg Bank- The use of egg donors for IVF has helped thousands of women achieve successful pregnancy when age-related decline, or other medical conditions, has not allowed success with treatment with their own eggs. Egg donor cycles have been traditionally performed with anonymous or known donors, who would undergo an IVF cycle with subsequent fertilization of the eggs with husband, partner or donor sperm. These fertilized eggs, or embryos, would be transferred to the recipient woman to achieve pregnancy. These cycles have involved significant cost and often limited access based on donor availability. The advent of improved egg freezing has allowed the development of frozen egg banks. Practices and labs throughout the country are establishing these banks of unfertilized frozen eggs, which offer the opportunity for enhanced access to donor eggs for more individuals and couples. With the growth of these banks, it is anticipated that costs will also be improved as this technology becomes more widely available.
Egg freezing represents an exciting advance in science, with a direct effect on the lives of human beings. This science has become an important part of treatment possibilities in reproductive medicine. As science and technology advance, it is anticipated that improved treatments, with less cost and more access, will help fulfill the dreams for all women and men who want to have a child and build a family.
Daniel Levine, MD, FACOG